Carburetor



pran D? 198380676 DCC. 29, F. H HElTGER 1,838,676

CARBURETOR Filed March f5, 1928 Patented Dec. 29, 1931 Examiner PAT-ENTOFFICE FRANK H. HEITGER, F FLINT, MICHIGAN CABBURETOR Application ledMarch 3, 1928. Serial No. 258,739.

This invention relates to certain new and useful improvements incarburetors and more particularly to carburetors for internal combustionengines used in connection with motor vehicles and the like where thespeed is variable, varying from a minimum speed to a high speed andwhere it is required to feed fuel to a carburetor posterior of thethrottle in the carbureting passage for the minimum or idling speed andto augment the fuel feed as the throttle is opened and before the mainfeed comes into action fully and is a companion application of myapplication filed March 3, 1928, Serial Number 258,738.

The main object of this invention is to provide a novel form of throttlevalve to be used in connection with the idling and transfer feeds sothat the proper mixture will be de livered to the internal combustionengine when the engine to which it is attached is idling.

Other and further objects and advantages of the invention will behereinafter set forth and the novel features thereof defined by theappended claims.

In the drawings,

Figure 1 is a vertical section through a carburetor constructed inaccordance with my invention showing the fuel bowl in elevation;

and

Figure 2 is a detail section through the carbureting passage showing thethrottle valve in elevation with its lip extending over the idlingpassages.

In the drawings I have shown a carburetor constructed substantially thesame as shown in my companion application comprising a body A having acarbureting passage B terminating at its upper end in an outlet B1 andat its lower end in a lateral air inlet B2 having a choker valve B3mounted therein for controlling the admission of air thereto in theusual manner.

Arranged in the carbureting passage is a Venturi tube 1 into whichextends a main fuel nozzle 2 which is in communication with a main fuelpassage 3 extending from a float bowl 4 which is of the ordinaryconstruction now in general use on carburetors, the flow of fuel fromthe bowl being controlled by a removable plug 5 having a calibratedorifice for allowing the maximum amount of fuel to pass therethrough.

An auxiliary fuel passage 6 is formed in one wall of the carburetingpassage and in the embodiment of my invention as shown, is supplied withfuel from an auxiliary reservoir 7 extending from the main fuel passage3. The lower end of the auxiliary fuel passage 6 is enlarged to receivethe upper end of the reservoir which is provided with a restrictedoutlet 8 subjected to suction and is adapted to feed fuel to theauxiliary passage 6 at substantially closed throttle position and tofeed air to the main fuel passage 3 as the throttle is moved into openposition substantially as described in the patent issued to Guthrie,December 5, 1916, No. 1,207,029. While I have shown the auxiliary fuelpassage 6 supplied with fuel from an auxiliary reservoir, I do not wishto limit myself to any particular means of supplying fuel thereto,

as I am aware that the same can be supplied with fuel from any source ofsupply, such as a well or directly from the fuel bowl without departingfrom the spirit of my invention which will be hereinafter fullydescribed.

The auxiliary fuel passage 6 terminates at its upper end in an annularchamber 9 formed by the end of a screw plug 10 working in a threadedbore formed in the wall of the carburetor as clearly shown. The annularchamber 9 is provided with superposed orifices 11 and 12 forming fueljets for idling and transfer, these openings communicating with thecarbureting passage B of the carburetor for supplying a fuel mixturethereto as will be later described. The passage 6 is provided with anair port 13 controlled by a screw 14: of the ordinary construction nowin general use on carburetors.

Extending transversely through the carbureting passage B slightly belowthe orifices 11 and 12 is a throttle valve shaft 15 carry ing abutterfly type of throttle valve 16 having a lip or projection 17 on oneedge provided with an opening 18 adapted to register with the idlingpassage 11, the solid portion of the lip being adapted to close thetransfer passage 12 when the throttle valve is in the closed position asshown so that the idling passage 11 is in constant communication withthe carbureting passage to the engine side of the throttle valve tosupply a fuel mixture to the engine when there is sufficient suction.

Vhen the throttle valve is slightly opened, the-transfer passage 12 isuncovered so as to allow both of these passages to supply fuel and whenthe throttle valve is moved into a still further open position, theidling passage 11 will feed air or a very weak mixture to the passage 12so as to obtain substantially the same results obtained in my companionapplication or weaker mixture from l2.

The throttle valve is so constructed that when it is in closed position,it is arranged at an angle and closes the carbureting passage and theorifice 12, by means of the lip 17 which has some spring to it asuitable stop mechanism being carried by the shaft of the throttle valveshaft constructed in substantially the same manner as shown in mycompanion application for preventing the throttle valve from beingsprained or distorted by moving too far into a closed or open position.

The throttle may be stamped or otherwise formed with a lip or projectionor the projection may be a separate member attached thereto having anopening formed therein, therefore I do not wish to limit myself to anyparticular manner of forming a throttle valve so long as it has aprojection with an opening for closing the orifice of the transferpassage and for allowing the other orifice to be in constantcommunication with the carbureting passage to the engine side of thethrottle.

In order to supply the proper amount of air for idling when the throttleis in closed position or substantially closed position, I provide thethrottle valve with an opening 19 to which air is adapted to pass fromthe anterior to the posterior side of the throttle and while I haveshown this means of supplying the air to the carbureting passage abovethe throttle, I am aware that the opposite wall of the carburetingpassage can be provided with an opening as shown in mv companionapplication for by passing air around the edge of the throttle forobtaining the desired result without opening the throttle for idlespeed.

While I have shown a particular construction for supplying fuel to theidling passage 6,1 do not wish to limit myself to the means shown as Iam aware that the fuel passage can be connected directly to any suitablesource of supply but when connected to a source of supply as hereinshown and as fully described in my companion application, the carburetorwill operate in substantially the same manner as that disclosed in mycompanion application tiled even date herewith with the exception thatinstead of having the upper orifice of the idling passage in constantcommunication with the carbureting passage when the throttle valve isclosed, I have the lower passage in constant communication with thecarbureting passage.

In the specication I have used the term transfer to mean the interval ordegree of throttle opening, where a single fixed idling feed of propermixture would be too lean to carry the motor before the main jet startedto feed and as the throttle is slightly opened; otherwise during thistime the mixture would be too lean from the idle feed alone.

From the foregoing description it will be seen that I have rovided acarburetor with a novel form o throttle valve which oooperates withidling or transfer orifices so as to supply the proper mixture when thethrottle valve is closed and as it moves from a closed to an openposition before the main feed comes into action.

Vhat I claim is:

1. The combination with a carburetor, of a carbureting passage, a mainfuel feed discharging into said passage, an auxiliary fuel passagehaving superposed openings for communicating with said carburetingpassage for idling and transfer, a throttle valve for closing saidcarbureting passage provided with a lip having an opening, said openingbeing adapted to register with the idle opening of said auxiliarypassage when said throttle valve is in closed position, means forfeeding air from anterior to posterior of the throttle, said throttlebeing adapted to move into open position on the said transfer port sidein the direcion of travel of fuel and air passing through saidcarburetor passage.

2. The combination with a carburetor, of a carbureting passage, a mainfuel feed discharging into said passage, an auxiliary fuel passagehaving superposed openings communicating with said carbureting passage,a throttle valve for closing said carbureting passage provided with alip having an opening, said opening being adapted to register with theidle openino' of said auxiliary passage when the throttle is in closedposition, means for feeding air from anterior to posterior of throttleindependent of throttle opening, said throttle being adapted to moveinto open position in the direction of travel of fuel and air passingthrough said carbureting passage on the said lip side of the throttle,the lower opening of said auxiliary passage being in constantcommunication with the carbureting passage.

3. The combination with a carburetor, of a carbureting passage providedwith a main fuel feed for feeding fuel into said passage, an auxiliaryfuel passage having superposed openings communicating with saidcarburetj signature.

FRANK H. HEITGER.

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